Brush connection.



A. R. MILLER. BRUSH CONNECTION. APPLICATION FILEDVDEC. 14| 9K6- 1,28 2,101. I Patented Oct-22, i918.

3 F 1 E 2 i H! )1, Z a z INVEN TOR. A. H..M.IL LE H a W ATTORNEY UNITED STATES PATENT OFFICE.

ARTHUR R. MILLER, 01 CLEVELAND, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TO NATIONAL CARBON COMPANY, INC., A CORPORATION 01? NEW YORK.

BRUSH CONNECTION.

tacts for electric switches and similar ap-.

paratus. Brushes for motors and generators,'as well as certain contacts for electric switches, are usually made of carbon or gra hite, and in nearlyv all cases a flexible con uctor is secured directly to the carbon block in order to give a low resistance contact.

In some respects my invention may be considered to be an improvement on the patent granted to Naydor, February 15, 1916, No. 1,171,630; but it is also applicable to other processes of securing flexible conductors or pigtails to brushes.

Referring to the drawings:

Figure 1 is a perspective view of a brush havin holes and recesses for receiving the pigtai connection.

Fig. 2 is a perspective view of'the slotted copper cup adapted to surround the pigtail inside of a recess in the brush.

Fig. 3 shows the brush after the pigtail has been tamped in osition.

Fig. 4 illustrates t e brush after the thin copper cu has been bent over the tamped strands o the pigtail. I

Fig. 5 illustrates the finished brush.

To appl my improved form of connection, a ho e 1 is bored partially through brush 2 and a smaller hole 3 is drilled to intersect the first hole or recess 1. A thin slotted copper cup 4 is then placed in the hole 1, with the slot 5 in line with hole 3. The pigtail is next pushed through the hole 3 and slot 5 and thence out through the protruding cup. The protruding strands of the pigtail are separated and then tamped or compacted into the cup after which it may Specification of Letters Patent.

Application filed December 14, '1918. Serial No. 186,842.

Patented Oct. 22, 1918.

be spun as described and claimed in the foresaid patentto N aydor, if desired.

After tamping the pigtail in position, as shown in .Fig. 3, the thm co er cup 4 is bent over the tamped strands of the pigtail as shown in Fig. 4, and thoroughly compacted against the, strands. Preferably the bent over portion is spun with a suitable tool until a smooth surface is obtained as illustrated in Fig. 5.

While it is preferable to slot the copper cup, a hole would serve the purpose.

Brushes having pigtail connections made in this way have a very low resistance, are mechanically strong, and are not injured by heat, as is the case with soldered connections particularly.

he copper cup ma be made of various thicknesses, but I pre er to make it of #36 B. & S. sheet copper which is substantially .005 in thickness. Preferably the cup is drawn or stamped into the shape illustrated in Fig. 1, although it would be possible to use a short cylinder cut from a thin walled copper tube either without a bottom or with the sides bent over to form a bottom portion.

The pigtails may be made of strands of any desired thickness, but I prefer to use strands of about #36 B. & S. gage, as the pigtail is then very readily tamped into place.

Having described my invention, what I claim is:

1. The method of attaching a stranded conductor to a brush, which consists in placing a thin metallic cylinder in a recess in the brush, compacting the strands of. the conductor solidly into said cylinder, bending over the protruding portion of the cylinder and compacting it solidly against the strands.

2. The method of attaching a stranded conductor to a brush, which consists in drilL ing two intersecting holes into the same, one being larger than the other, to form a seat for the end of the conductor, inserting a thin slotted metallic cup in the said larger hole, passing a stranded conductor through both of said holes, wadding one end of it in the larger hole, bending over the protruding end of said cup and spmning the cup and wedded portion of the Eigtail into a, 5 compact mass within the brus 3. A brush having a recess therein, a thin metallic cup in said recess, a pigtail comacted within said cup, the end of the cup ing bent over against the portion of the pigtail and compacted thereagainst.

In testimony whereof, I hereunto afiix my signature.

A. R. MILLER. 

